SELECT 
  product_prices.product_id, 
  MIN(
    IF(
      product_prices.percentage_discount = 0, 
      product_prices.price, 
      product_prices.price - (
        product_prices.price * product_prices.percentage_discount
      )/ 100
    )
  ) AS price 
FROM 
  product_prices 
WHERE 
  product_prices.product_id IN (
    454433, 454440, 455142, 456484, 457048, 
    458367, 459103, 460481, 460992, 461008, 
    461741, 463632
  ) 
  AND product_prices.lower_limit = 1 
  AND product_prices.usergroup_id IN (0, 1) 
GROUP BY 
  product_prices.product_id

Query time 0.00081

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "11.47"
    },
    "grouping_operation": {
      "using_filesort": false,
      "table": {
        "table_name": "product_prices",
        "access_type": "range",
        "possible_keys": [
          "usergroup",
          "product_id",
          "lower_limit",
          "usergroup_id"
        ],
        "key": "product_id",
        "used_key_parts": [
          "product_id"
        ],
        "key_length": "3",
        "rows_examined_per_scan": 12,
        "rows_produced_per_join": 1,
        "filtered": "10.00",
        "index_condition": "(`goimagine`.`product_prices`.`product_id` in (454433,454440,455142,456484,457048,458367,459103,460481,460992,461008,461741,463632))",
        "cost_info": {
          "read_cost": "11.36",
          "eval_cost": "0.12",
          "prefix_cost": "11.48",
          "data_read_per_join": "28"
        },
        "used_columns": [
          "id",
          "product_id",
          "price",
          "percentage_discount",
          "lower_limit",
          "usergroup_id"
        ],
        "attached_condition": "((`goimagine`.`product_prices`.`lower_limit` = 1) and (`goimagine`.`product_prices`.`usergroup_id` in (0,1)))"
      }
    }
  }
}

Result

product_id price
454433 15.00000000
454440 15.00000000
455142 18.00000000
456484 18.00000000
457048 18.00000000
458367 18.00000000
459103 21.00000000
460481 18.00000000
460992 18.00000000
461008 18.00000000
461741 20.00000000
463632 18.00000000